The invention relates to a vibration measurement system for frequency-selective oscillation measurement.
A system such as this is used, for example, for automation and drive technology where it can preferably be used for state monitoring of components that are subject to wear. Furthermore, the invention can be used to monitor manufacturing processes which can be disturbed by an oscillating environment. In addition, the invention can be used to characterize oscillating systems and components.
Production failures resulting from unexpected machine defects can cause direct damage and consequential damage at a considerable level, depending on the field and the nature of the process. In order to improve the reliability of production machines and machine tools, process installations, transport systems and the like, and therefore to reduce downtimes of these production facilities, premature wear and defect identification are therefore becoming ever more important.
For example, in the case of electrical machines, a failure of the production means or of one of its components, (for example the bearings) is frequently indicated by a change in the oscillation behavior. These changes can be detected by vibration analysis. This allows the relevant components to be replaced in good time before the entire system fails, thus avoiding a relatively long production shutdown.
Depending on the frequency range of the relevant oscillations, the frequencies can be measured selectively or can be determined over a broad bandwidth followed by Fourier analysis. For technical reasons, frequency-selective sensors can be used better for analysis of relatively high-frequency oscillations (>1 kHz). Low-frequency oscillations (<1 kHz) are nowadays generally detected by means of a broadband piezoceramic sensor. The individual frequency components are then determined from the measurement signal by means of a Fast Fourier Transformation (FFT) carried out in software or hardware.
Particularly in automation and drive technology, brief shocks lead to structure-borne sound signals with a broadband spectrum which extends over several hundred kilohertz. This secondary excitation, which also acts directly on the receiver structure of the coupled oscillator structure, leads to corruption of the actual measurement signal.